The invention relates to a ship loader or unloader including an essentially vertically extending region that can be displaced along a boom. At its lower end, this region cooperates with an essentially horizontally extending region. The ship loader or unloader further includes a bucket mechanism that is driven by means of chains and is guided on rollers in the vertical and horizontal regions.
DE-OS [German Unexamined Published Patent Application] 3,029,863 discloses a movable ship unloader for the continuous removal of bulk materials by means of an endless vertical conveyor in the form of a bucket mechanism formed at a vertical carrier. The lower end of the vertical carrier is rigidly connected with an essentially horizontal take-up arm and has an L shape. A bucket chain is guided around the vertical carrier and the take-up arm in such a manner that the bulk material can be conveyed continuously and without transfer from the region of the horizontal receiving arm through the region of the vertical carrier to a radially configured upper discharge end provided in the extension thereof and from there to a horizontally arranged turntable or ring conveyor that encloses the upper end and is mounted concentrically therewith.
The vertical conveyor constructed of a vertical region and a horizontal region is supported in the region of its upper end at the free end of a boom. In dependence on the quantity of bulk material to be unloaded, this vertical conveyor has a very high weight so that relatively large counterweights must be provided on the other side of the boom. These devices can be used relatively without problems for ships in port where there is little wave action and they are also suitable for high bulk material discharges. However, if water conditions exist which cause the ship's body to be raised and lowered at given intervals or in surges, difficulties arise in adapting the vertical conveyor to these movements. Although it is possible to further increase the counterweight such an increase requires the consideration of greater expenditures for controls, with the control system not necessarily being able to adapt the relatively heavy vertical conveyor to the rapid fluctuations in the ship's movements. Consequently, the danger continues to exist that collisions might occur between the vertical conveyor and the ship which, under certain circumstances, could lead to damage to one or the other or both.